Annoying problem in browser with Custom Community theme with buddypress enabled

Originally when customizing Custom Community theme, there is the text box under “CSS” for adding custom code. If you click there, you would get the js error below, making it impossible to access the text box. The author told me:

This sounds like a conflict with the thickbox JS that wordpress uses.
I would disable any new plugins and try it again to figure out what one it might be.
The JS file in question is in the wordpress core and not the theme its self.

I disabled the Shareholic bookmarking plugin, which seemed to be the culprit & the problem was solved.

With time, though I noted the issue had reappeared & I simply could not make out the culprit plugin. So I decided to disable ALL, and activate them one by one in the following order, while checking if the mouse could normally access the CSS textarea: